Justice League of America Vol 1 88

"The Last Survivors of Earth!": With the destruction of the continent of Mu, its people had escaped into space on an ark-like ship. Now they return to Earth, to find their former home inhabited by 3½ billion humans whom they deem too inferior to be allowed to live. They cause destructive natural

Synopsis for "The Last Survivors of Earth!"

With the destruction of the continent of Mu, its people had escaped into space on an ark-like ship. Now they return to Earth, to find their former home inhabited by 3½ billion humans whom they deem too inferior to be allowed to live. They cause destructive natural forces to ravage various locales, and the Justice League is gathered to try to prevent disaster.

However, while each member believes one of his team-mates is responsible for saving the world, it is actually three ordinary people who defeat the Muans. An Iranian leader and a Vietnamese woman unwittingly destroy artifacts being used to cause the catastrophes, while an American youth, whom the Muans kidnap, literally throws a wrench into their machinery, and wrecks their ship.